Process of manufacturing centrifugally-cast-iron pipe and apparatus therefor



Dec. 13, 1927. 1,652,829

` A. LOSEY I PROCESS 0F MANUFACTURING CENTRIFUGALLY CAST CAST IRON PIPE AND APPARATUS THEREFOR Filed March 24. 1925 www lll

[Patented Dee. 13, 1927.

UNITED STATES 1,652,829 PATENT OFFICE.

ARTHUR LOSEY, OFA JERSEY CITY, NEW JERSEY, ASSIGNOB TO UNITED STATESl CAST IRON PIPE & FOUNDRY COMPANY, 0F BURLINGTON, NEW JERSEY, A CORPORATION OF NEW JERSEY.

PROCESS. OF MANUFACTURING CENTRIFUGALIlY-CAST CAST-IRON PIPE AND APPARA- i TUS THEBEFOB.

Application led March 24, 1925. Serial No. 17,962.

rIhis invent-ion relates to improvements in process of manufacturing centrifugally cast casteiron pipe and apparatus therefor.

The principal object of my invention is' to produce centrifugally cast cast-iron pipe which is tougher and more ductile than that made by other processes now in use. i

lVith the above and other objects in view, the present invention broadly considered, provides certain novel features which make possible the economical production of centrifugally cast cast-iron pipe.

In the manufacture of centrifugally cast pipe it is customary to anneal the castiron pipe after removal from the metal moulds in order to convert the chilled outer portion of white iron into softergrey iron, whereas: one novel feature of my invention resides in the provision of a process by which the annulus of white iron, chilled during the casting period, instead of being converted into grey iron by annealing, is converted into malleable iron by reactions brought about by heated iron oxide in contact therewith during the annealing operation.

Another novel feature of my invention resides in the provision of a process of subjecting heated centrifugally cast cast-iron pipe to the action of heated iron oxide which 1s pro essively exposed, rejected and rearrange during transit thru the furnace.

Another novel feature of my invention resides in the rovision of means by which said process o converting said annulus of white iron to malleableiron may be effected.

Another novel feature of my invention resides in the provision of means by which the iron' oxide in contact with the surface being malleableized may be progressively released and rearranged during its transit thru, the furnace in order that said process mayproceed with great rapidity.

Still another novel feature of my invention resides in the provision of means by which the contaminated and reduced iron oxide may be revivified for continuous malleableizing use.

Apparatus suitable for carrying out my process is illustrated in the accompanying drawing in which,

Fig. l is a sectional plan of malleableizing furnace anda conventional lan of auxiliary equipment showing malleab eizing cells.

Fig. 2 is a longitudinal sectional elevation thru malleableizing furnace and cooling skids showing malleableizing cells.

Fig. 3 is a transverse sectional elevation thru malleableizing furnace showing malle ableizing cell.

Fig. 4 is a transverse section thru one of the malleableizing cells with centrifugally cast cast-iron pipe and iron oxide in position, a portion of the furnace rail being shown.

I It should be understood that the illustrations are suggestive and the invention may be embodied in various forms other than those shown.

Referring to the drawing, the operation of process -andapparatus in accordance with my invention may be as follows;

Iron oxide having been heated in kiln 5 to temperature at which it will readily form a reaction with carbon, is released at spout 6 and guidedthru funnel 7 enters malleableizing cell 8 in which a centrifugally cast castiron pipe 9 has been placed, said pipe having been received in heatedcondition from a centrifugal casting machine served by monorail 10.

The malleableizing cell is then placed on rails l1 of malleableizing furnace 12 into which it is lrolled after raisin door 13. Chain dogs 14 serve to push t e cells as they slowly roll thru the furnace. The malleableizing cell and the cast-iron pipe placed therein receive heat from the furnace gases and serve to heat iron oxide 15 shown in Fig. 4 while annulus of white iron 16 is converted into malleable iron by action of iron oxide, the particles of which are progressively exposed, rejected at 17 and rearranged at 18 as the cell is rolled thru the furnace. As the combined carbon changes to graphitic carbon, the heated iron oxide Fez()3 having greater affinity for carbon than has the white cast-iron, the removal of carbon from the annulus of white iron proceeds as a gradual combustion according to reactions which are influenced by lthe temperature of the carbon and oxide, such as at 7 50 degrees Fahr. the reaction becomes 3CD-t2 Fe which is of a reducing character and does not injure the iron pipe, while the middle strata is undergoing more favorable conditions which revent formation of excessive graphitic car on flakes. The exposure, re-

, carbon during the process, thereby producing heat, which is continued` for considerable time after the malleableizi'ng cell opens hinged door 19 and rolls along cooling skids 20. A monorail 21 serves pipe extractor l22 and monorail 23 enables the extracted pipe to be transported to the inspection and testing department, likewise monorail 24. serves for conveying the malleableizing cell and its contents of iron oxide to hopper 25 where the oxide is discharged into the kiln. The

oxidizing atmosphere present during com-A bustion inv the kiln serves to heat the contaminated iron oxide thereby consuming the absorbed carbon and oxidizing the iron particles which had previously been in the form of iron oxide, thus rendering the oxide capable of being repeatedly utilized in the ce s.

The malleableizing cell is availablefor reception vof another centrifugally cast castiron pipe and may againv be placed where heated iron oxide may be released at the spout and the circuit continued.

It should be yunderstood that the above described apparatus may be used for analogous operations and, consequently While it 0 is herein described by reference to a particular application, this description is not intended as a limitation of the present invention. It is obvious that a mineral oxide` other than iron oxide may be employed for removing the carbon from 'the annulus 0i White iron.

Various changes may be made in process and apparatus by those skilled in the art, without departing from my invention, but what I claim as being new and desire to secure by Letters Patent is;

1. The method of malleableizing iron castings in which the casting is subjected to 'the action of a heatedlmass of metallic oxide the particles of which are rearranged in lthe mass during the operation so that deoxidized particles in contact with the casting are removed therefrom and fresh particles brought in contact therewith.

2. The method of malleableizing centrifugally cast cast iron pipe in which the exterior of the casting is subjected to the action of a heated mass of metallic oxide the particles of which are rearranged in the mass during the operation so that deoxidized particles in contact with the exterior of the pipe are removed therefrom and fresh particles brought in ycontact; therewith.

In testimony whereof, havesigned my name to this specification, this 21st day of March 1925.

' ARTHUR LOSEY. 

